PHP開発でユーザーの認証と認可を処理する方法

<?php
$username = 'admin';
$password = '123456';

if (isset($_SERVER['PHP_AUTH_USER']) && isset($_SERVER['PHP_AUTH_PW'])) {
    if ($_SERVER['PHP_AUTH_USER'] == $username && $_SERVER['PHP_AUTH_PW'] == $password) {
        echo '认证成功';
    } else {
        header('WWW-Authenticate: Basic realm="My Realm"');
        header('HTTP/1.0 401 Unauthorized');
        echo '用户名或密码错误';
        exit;
    }
} else {
    header('WWW-Authenticate: Basic realm="My Realm"');
    header('HTTP/1.0 401 Unauthorized');
    echo '请输入用户名和密码';
    exit;
}
?>

<?php
session_start();

$username = 'admin';
$password = '123456';

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $input_username = $_POST['username'];
    $input_password = $_POST['password'];

    if ($input_username == $username && $input_password == $password) {
        $_SESSION['username'] = $username;
        echo '登录成功';
    } else {
        echo '用户名或密码错误';
    }
}

if (isset($_SESSION['username'])) {
    echo '当前用户：' . $_SESSION['username'];
}
?>

<?php
require_once 'vendor/autoload.php';

$clientId = 'YOUR_CLIENT_ID';
$clientSecret = 'YOUR_CLIENT_SECRET';
$callbackUrl = 'YOUR_CALLBACK_URL';

$provider = new LeagueOAuth2ClientProviderGoogle([
    'clientId' => $clientId,
    'clientSecret' => $clientSecret,
    'redirectUri' => $callbackUrl,
]);

if (!isset($_GET['code'])) {
    $authUrl = $provider->getAuthorizationUrl();
    $_SESSION['oauth2state'] = $provider->getState();
    header('Location: ' . $authUrl);
    exit;
} elseif (empty($_GET['state']) || ($_GET['state'] !== $_SESSION['oauth2state'])) {
    unset($_SESSION['oauth2state']);
    exit('认证失败');
} else {
    $token = $provider->getAccessToken('authorization_code', [
        'code' => $_GET['code'],
    ]);
    $user = $provider->getResourceOwner($token);
    $username = $user->getEmail();

    echo '认证成功，用户名：' . $username;
}
?>

<?php
$permissions = [
    'admin' => ['create', 'edit', 'delete'],
    'user' => ['view'],
];

function hasPermission($role, $permission)
{
    global $permissions;

    if (isset($permissions[$role]) && in_array($permission, $permissions[$role])) {
        return true;
    }

    return false;
}

$role = 'user';
$permission = 'view';

if (hasPermission($role, $permission)) {
    echo '用户具有该权限';
} else {
    echo '用户没有该权限';
}
?>

<?php
$roles = [
    'admin' => ['administer users', 'manage content'],
    'editor' => ['manage content'],
    'author' => ['write articles'],
    'user' => ['view articles'],
];

function hasAccess($userRoles, $permission)
{
    global $roles;

    foreach ($userRoles as $role) {
        if (isset($roles[$role]) && in_array($permission, $roles[$role])) {
            return true;
        }
    }

    return false;
}

$userRoles = ['user'];
$permission = 'view articles';

if (hasAccess($userRoles, $permission)) {
    echo '用户具有该权限';
} else {
    echo '用户没有该权限';
}
?>